Since prehistoric times, ovens have been used in baking bread and similar dough products and in various other types of food preparation activities. A wide variety of oven types have been successfully employed, including open hearth types, deck types, tray types, rack types, and more recently conveyorized ovens. Conveyorized ovens are particularly adapted to modern automated bakeries wherein conveyor systems transport dough receiving pans through the various components of the bakery to produce food products on a continuous basis.
The present invention relates to an air circulation and exhaust control system that is particularly adapted for use in conjunction with conveyorized ovens. In accordance with the broader aspects of the invention, a conveyor transports dough receiving trays through an enclosure defining the oven interior. A plurality of ribbon burners located at predetermined points adjacent the path of the conveyor burn a mixture of natural gas and air to maintain a predetermined elevated temperature within the oven interior. The heated air tends to rise within the oven interior.
An inlet plenum has inlet apertures situated above the ribbon burners. A circulation fan draws the heated air through the inlet apertures and the inlet plenum and discharges the air through outlet passages to outlet plenums. The outlet plenums direct the air to a plurality of discharge tubes situated at predetermined points adjacent the conveyor. Thus, the heated air generated by the ribbon burners is recirculated within the oven interior more effectively to heat the dough contained within the dough receiving pans and to assure that neither "hot spots" nor "cold spots" exist within the oven interior.
The enclosure surrounding the conveyor includes a top panel enclosing the top of the oven interior. An exhaust blower assembly controls the flow of exhaust air out of the oven interior through discharge ports in the top panel. The exhaust blower assembly speed is regulated in accordance with the flow rate of air and gas into the ribbon burners. In this manner, the escape of heated gases from the oven interior is regulated to limit heat loss while simultaneously maintaining the desired atmosphere within the oven interior.